4,367 research outputs found
A system of three transiting super-Earths in a cool dwarf star
We present the detection of three super-Earths transiting the cool star
LP415-17, monitored by K2 mission in its 13th campaign. High resolution spectra
obtained with HARPS-N/TNG showed that the star is a mid-late K dwarf. Using
spectral synthesis models we infer its effective temperature, surface gravity
and metallicity and subse- quently determined from evolutionary models a
stellar radius of 0.58 R Sun. The planets have radii of 1.8, 2.6 and 1.9 R
Earth and orbital periods of 6.34, 13.85 and 40.72 days. High resolution images
discard any significant contamination by an intervening star in the line of
sight. The orbit of the furthest planet has radius of 0.18 AU, close to the
inner edge of the habitable zone. The system is suitable to improve our
understanding of formation and dynamical evolution of super-Earth systems in
the rocky - gaseous threshold, their atmospheres, internal structure,
composition and interactions with host stars.Comment: Accepted for publication in MNRAS Letter
The highly prevalent BRCA2 mutation c.2808_2811del (3036delACAA) is located in a mutational hotspot and has multiple origins
BRCA2-c.2808_2811del (3036delACAA) is one of the most reported
germ line mutations in non-Ashkenazi breast cancer patients. We
investigated its genetic origin in 51 Spanish carrier families that
were genotyped with 11 13q polymorphic markers. Three independent
associated haplotypes were clearly distinguished accounting for
23 [west Castilla y León (WCL)], 20 [east Castilla y León (ECL)]
and 6 (South of Spain) families. Mutation age was estimated with
the Disequilibrium Mapping using Likelihood Estimation software
in a range of 45–68 and 45–71 generations for WCL and ECL haplotypes,
respectively. The most prevalent variants, c.2808_2811del
and c.2803G > A, were located in a double-hairpin loop structure
(c.2794–c.2825) predicted by Quikfold that was proposed as a mutational
hotspot. To check this hypothesis, random mutagenesis was
performed over a 923 bp fragment of BRCA2, and 86 DNA variants
were characterized. Interestingly, three mutations reported in the
mutation databases (c.2680G > A, c.2944del and c.2957dup) were
replicated and 20 affected the same position with different nucleotide
changes. Moreover, five variants were placed in the same hairpin loop
of c.2808_2811del, and one affected the same position (c.2808A > G).
In conclusion, our results support that at least three different mutational
events occurred to generate c.2808_2811del. Other highly
prevalent DNA variants, such as BRCA1-c.68_69delAG, BRCA2-
c.5946delT and c.8537delAG, are concentrated in hairpin loops, suggesting
that these structures may represent mutational hotspots
Singer identification using perceptual features and cepstral coefficients of an audio signal from Indian video songs
Evaluation of polygenic risk scores for breast and ovarian cancer risk prediction in BRCA1 and BRCA2 mutation carriers
Background: Genome-wide association studies (GWAS) have identified 94 common single-nucleotide polymorphisms (SNPs) associated with breast cancer (BC) risk and 18 associated with ovarian cancer (OC) risk. Several of these are also associated with risk of BC or OC for women who carry a pathogenic mutation in the high-risk BC and OC genes BRCA1 or BRCA2. The combined effects of these variants on BC or OC risk for BRCA1 and BRCA2 mutation carriers have not yet been assessed while their clinical management could benefit from improved personalized risk estimates.
Methods: We constructed polygenic risk scores (PRS) using BC and OC susceptibility SNPs identified through population-based GWAS: for BC (overall, estrogen receptor [ER]-positive, and ER-negative) and for OC. Using data from 15 252 female BRCA1 and 8211 BRCA2 carriers, the association of each PRS with BC or OC risk was evaluated using a weighted cohort approach, with time to diagnosis as the outcome and estimation of the hazard ratios (HRs) per standard deviation increase in the PRS.
Results: The PRS for ER-negative BC displayed the strongest association with BC risk in BRCA1 carriers (HR = 1.27, 95% confidence interval [CI] = 1.23 to 1.31, P = 8.2 x 10(53)). In BRCA2 carriers, the strongest association with BC risk was seen for the overall BC PRS (HR = 1.22, 95% CI = 1.17 to 1.28, P = 7.2 x 10(-20)). The OC PRS was strongly associated with OC risk for both BRCA1 and BRCA2 carriers. These translate to differences in absolute risks (more than 10% in each case) between the top and bottom deciles of the PRS distribution; for example, the OC risk was 6% by age 80 years for BRCA2 carriers at the 10th percentile of the OC PRS compared with 19% risk for those at the 90th percentile of PRS.
Conclusions: BC and OC PRS are predictive of cancer risk in BRCA1 and BRCA2 carriers. Incorporation of the PRS into risk prediction models has promise to better inform decisions on cancer risk management
Evaluation of different bowel preparations for small bowel capsule endoscopy: a prospective, randomized, controlled study
To obtain an adequate view of the whole small
intestine during capsule endoscopy (CE) a clear liquid diet and overnight fasting
is recommended. However, intestinal content can hamper vision in spite of these
measures. Our aim was to evaluate tolerance and degree of intestinal cleanliness
during CE following three types of bowel preparation. PATIENTS AND METHODS: This
was a prospective, multicenter, randomized, controlled study. Two-hundred
ninety-one patients underwent one of the following preparations: 4 L of clear
liquids (CL) (group A; 92 patients); 90 mL of aqueous sodium phosphate (group B;
89 patients); or 4 L of a polyethylene glycol electrolyte solution (group C; 92
patients). The degree of cleanliness of the small bowel was classified by blinded
examiners according to four categories (excellent, good, fair or poor). The
degree of patient satisfaction, gastric and small bowel transit times, and
diagnostic yield were measured. RESULTS: The degree of cleanliness did not differ
significantly between the groups (P = 0.496). Interobserver concordance was fair
(k = 0.38). No significant differences were detected between the diagnostic
yields of the CE (P = 0.601). Gastric transit time was 35.7 +/- 3.7 min (group
A), 46.1 +/- 8.6 min (group B) and 34.6 +/- 5.0 min (group C) (P = 0.417).
Small-intestinal transit time was 276.9 +/- 10.7 min (group A), 249.7 +/- 13.1
min (group B) and 245.6 +/- 11.6 min (group C) (P = 0.120). CL was the best
tolerated preparation. Compliance with the bowel preparation regimen was lowest
in group C (P = 0.008). CONCLUSIONS: A clear liquid diet and overnight fasting is
sufficient to achieve an adequate level of cleanliness and is better tolerated by
patients than other forms of preparation
HLA association with the susceptibility to anti-synthetase syndrome
Objective: To investigate the human leukocyte antigen (HLA) association with anti-synthetase syndrome (ASSD). Methods: We conducted the largest immunogenetic HLA-DRB1 and HLA-B study to date in a homogeneous cohort of 168 Caucasian patients with ASSD and 486 ethnically matched healthy controls by sequencing-based-typing. Results: A statistically significant increase of HLA-DRB1*03:01 and HLA-B*08:01 alleles in patients with ASSD compared to healthy controls was disclosed (26.2% versus 12.2%, P = 1.56E–09, odds ratio–OR [95% confidence interval–CI] = 2.54 [1.84–3.50] and 21.4% versus 5.5%, P = 18.95E–18, OR [95% CI] = 4.73 [3.18–7.05]; respectively). Additionally, HLA-DRB1*07:01 allele was significantly decreased in patients with ASSD compared to controls (9.2% versus 17.5%, P = 0.0003, OR [95% CI] = 0.48 [0.31–0.72]). Moreover, a statistically significant increase of HLA-DRB1*03:01 allele in anti-Jo-1 positive compared to anti-Jo-1 negative patients with ASSD was observed (31.8% versus 15.5%, P = 0.001, OR [95% CI] = 2.54 [1.39–4.81]). Similar findings were observed when HLA carrier frequencies were assessed. The HLA-DRB1*03:01 association with anti-Jo-1 was unrelated to smoking history. No HLA differences in patients with ASSD stratified according to the presence/absence of the most representative non-anti-Jo-1 anti-synthetase autoantibodies (anti-PL-12 and anti-PL-7), arthritis, myositis or interstitial lung disease were observed. Conclusions: Our results support the association of the HLA complex with the susceptibility to ASSD
Combined search for the quarks of a sequential fourth generation
Results are presented from a search for a fourth generation of quarks
produced singly or in pairs in a data set corresponding to an integrated
luminosity of 5 inverse femtobarns recorded by the CMS experiment at the LHC in
2011. A novel strategy has been developed for a combined search for quarks of
the up and down type in decay channels with at least one isolated muon or
electron. Limits on the mass of the fourth-generation quarks and the relevant
Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a
simple extension of the standard model with a sequential fourth generation of
fermions. The existence of mass-degenerate fourth-generation quarks with masses
below 685 GeV is excluded at 95% confidence level for minimal off-diagonal
mixing between the third- and the fourth-generation quarks. With a mass
difference of 25 GeV between the quark masses, the obtained limit on the masses
of the fourth-generation quarks shifts by about +/- 20 GeV. These results
significantly reduce the allowed parameter space for a fourth generation of
fermions.Comment: Replaced with published version. Added journal reference and DO
Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV
A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay
channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7
TeV is presented. The data were collected at the LHC, with the CMS detector,
and correspond to an integrated luminosity of 4.6 inverse femtobarns. No
significant excess is observed above the background expectation, and upper
limits are set on the Higgs boson production cross section. The presence of the
standard model Higgs boson with a mass in the 270-440 GeV range is excluded at
95% confidence level.Comment: Submitted to JHE
Measurement of the t t-bar production cross section in the dilepton channel in pp collisions at sqrt(s) = 7 TeV
The t t-bar production cross section (sigma[t t-bar]) is measured in
proton-proton collisions at sqrt(s) = 7 TeV in data collected by the CMS
experiment, corresponding to an integrated luminosity of 2.3 inverse
femtobarns. The measurement is performed in events with two leptons (electrons
or muons) in the final state, at least two jets identified as jets originating
from b quarks, and the presence of an imbalance in transverse momentum. The
measured value of sigma[t t-bar] for a top-quark mass of 172.5 GeV is 161.9 +/-
2.5 (stat.) +5.1/-5.0 (syst.) +/- 3.6(lumi.) pb, consistent with the prediction
of the standard model.Comment: Replaced with published version. Included journal reference and DO
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